In orthodontics, treatments for achieving alignment of malposed teeth in a patient include applying orthodontic appliances to the patient's teeth, such as pre-shaped orthodontic wire attached to the brackets which are themselves attached to the teeth. The wires are typically made from shape memory alloys which have the ability to recover their shape after being deformed. This re-shaping occurs at a predetermined temperature, usually around 38° C. Shape memory alloys used in orthodontic archwires include nickel-titanium alloys (e.g. Nitinol™), beta-titanium alloys, and copper nickel-titanium alloys.
The wires are typically pre-shaped into a desired shape by forming bends at desired positions and with desired angles, heating under tension, and super-cooling. The heating step typically comprises electric heating. Once pre-shaped, the wire is attached to the brackets by bending its shape to conform to the general shape of the malposed teeth. When the wire warms to mouth temperature it reverts to its original shape thereby exerting a force on the teeth to which it is attached to move them.
At least the bending portion of the pre-shaping process can be achieved manually or using bending apparatus such as those described in U.S. Pat. No. 6,612,143, U.S. Pat. No. 6,732,558, U.S. Pat. No. 6,755,064, U.S. Pat. No. 6,860,132, U.S. Pat. No. 7,076,980, U.S. Pat. No. 7,283,891 and US2010275668.
In certain pre-shaping methods, the desired bend in the orthodontic appliance is achieved by iteratively bending the orthodontic appliance, and assessing the acquired bend until the desired bend is achieved. This can take many iterations which has associated inconveniences of material property degradation in the orthodontic appliance, as well as increased time and cost per orthodontic appliance manufacture.
U.S. Pat. No. 6,612,143 describes a robotic bending apparatus for bending archwires and other types of elongate, bendable medical devices into a desired configuration and includes a first gripping tool and a moveable gripping tool. The first gripping tool can be either fixed with respect to a base or table for the robot or positioned at the end of robot arm. The moveable gripping tool is mounted to the end of a moveable robot arm having a proximal portion also mounted to the base. The robot preferably comprises a six axis bending robot, in which the distal end of the moveable arm can move relative to the fixed gripping tool about three translational axes and three rotational axes. The gripping tools preferably incorporate force sensors which are used to determine overbends needed to get the desired final shape of the archwire. The robot may also include a resistive heating system in which current flows through the wire while the wire is held in a bent condition to heat the wire and thereby retain the bent shape of the wire. A magazine for holding a plurality of straight archwires needing to be bent and a conveyor system for receiving the wires after the bending process is complete are also described. The robot bending system is able to form archwires with any required second and third order bends quickly and with high precision. As such, it is highly suitable for use in a precision appliance-manufacturing center manufacturing a large number of archwires (or other medical devices or appliances) for a distributed base of clinics.
U.S. Pat. No. 9,901,705 describes an apparatus, system, and method for creating a curvature on a medical device during a medical procedure, for example, selecting a curvature from a curve database, customizing the curvature for a specific patient anatomy, and applying the curvature to the medical device during the medical procedure.
It is an object of the present technology to ameliorate at least some of the inconveniences present in the prior art.